The World Universities Debating Championship (WUDC) is the world's largest debating tournament, and one of the largest annual international student events in the world.[1] It is a parliamentary debating event, held using either the British Parliamentary Debate format (involving four teams of two people in each debate) or the American Parliamentary Debate format (two teams of two people).[2] Each year, the event is hosted by a university selected by the World Universities Debating Council. The tournament is colloquially referred to as "Worlds" and the winners of the open competition acknowledged as the "world champions".

The most recent edition of the tournament took place in The Hague in January 2017. The current World Champions are Emma Johnstone and James Leeder representing Sydney University. The English as a Second Language (ESL) competition was won by Tom Manor and Noam Dahan of Tel Aviv University, while Belgrade University (Milos Majanovic and Teodora Resetar) won the English as a Foreign Language (EFL) tournament.

The championship is usually held in the days following Christmas, since many of the institutions attending from the Northern Hemisphere where the championship originated take vacations at this time. Although many countries that do not celebrate Christmas have become participants at the competition, the timing has remained the same. In most recent years, the nine preliminary rounds of the tournament have been held over three days from 29–31 December, with the elimination rounds being held on 2 January and the Grand Final on 3 January.

In recent years, the championship has varied from about 150 to 400 teams, depending on the capacity of the host institution. With judges and organisers, this involves 500 to 1,000 participants in all.

The competition involves nine preliminary rounds, which become "power-paired" as the tournament progresses, matching the strongest-performing teams against each other. Two teams form the "government" ("proposition" in the UK and North America) and two the "opposition" in each debate room. The process of scoring and pairing these teams is known as "tabbing". The scoring of teams is done by judges, most of whom are students or former students from the competing institutions, who return "ballots" with their scores to the adjudication team, led by a Chief Adjudicator who is assisted by one or more deputies. The deputies are not members of the host institution.

The nine preliminary rounds are followed by a "break" at which the teams proceeding to elimination rounds are announced. This is traditionally done on New Year's Eve, although this is subject to the timing of the tournament. In the current tournament format, the top 16 teams from the preliminary rounds proceed to the octo-final round. The teams ranked 17-48 also break into a partial double octo-final round, and the winning teams from this round join the teams ranked 1-16 in the octo-finals. While preliminary rounds are usually judged by up to three judges, the break rounds are judged by panels of five, and the finals by panels of seven.

Separate breaks are announced for the English-as-a-second language (ESL) and English-as-a-foreign language (EFL) team competitions, for the individual public speaking competition, and the "World Masters" tournament which is participated in by judges (most of whom are no longer students) representing the countries where they studied or of which they are citizens. In addition, a comedy competition is also open to all participants in Worlds.

The World Universities Debating Council consists of representatives of every country that competes at the World Universities Debating Championship. Each country selects one council delegate (the national debating association president, or selected from the participants at Worlds). The Council is responsible for setting the rules and awarding the right to host the championships.

The Council formerly operated not unlike the United Nations Security Council, with seven nations holding "charter member status" – the United States, Canada, England, Scotland, Ireland, Australia and New Zealand. A two-thirds majority of these countries was required for changes to the championship's constitution, irrespective of how the general vote was tallied. However, as the number of non-charter nations attending grew, many fielding far more teams than some of the upper tier, and the championship began being hosted outside the Charter nations, pressure grew for the distinction to be eliminated.

The modern championship grants voting strength of between one and four votes per country, based on numbers of institutions attending recent championships. To allow for fluctuations in participation due to the financial difference in attending championships nearer or further in succeeding years, nations lose or gain their voting strength gradually.

The Trans-Atlantic University Speech Association held tournaments in London (1976 and 1978) and at McGill University, Montreal, in 1977. Chicago was to hold a tournament in 1979 but this was postponed and then abandoned. A "World Debating Festival", sponsored by Honeywell was held in Sydney in 1978. The TAUSA event attracted mostly Northern Hemisphere tournaments, the Honeywell was largely Southern Hemisphere.